Strategy and tactics of disarming GHG at the source: N2O reductase crops

Nitrous oxide (N2O), the third most abundant greenhouse gas (GHG), is highly stable and plays a significant role in stratospheric ozone destruction. The primary anthropogenic source of N2O stems from use of nitrogen fertilizers in soil. The bacterial enzyme nitrous oxide reductase (N2OR), naturally found in some soils, is the only known enzyme capable of catalyzing the final step of the denitrification pathway, conversion of N2O to N2. In this opinion, we discuss potential biology-based strategies to reduce N2O by amplifying the amount of available enzyme catalyst in agri-system environments during crop growth and in post-harvest detritus. N2OR from Pseudomonas stutzeri has been tested in transgenic plants with promising results. Such seed-borne phytoremediation systems targeted towards GHGs merit field testing.